Diet and acne: review of the evidence from 2009 to 2020

Background: Dietary habits may play a non-negligible role in the development, duration, and severity of acne, as shown in past critical review articles on such association. Methods: The aim of this systematic review is to supplement data available on scientific literature spanning the last 10 years by inserting the keywords “acne” or “acne vulgaris” and “diet”, “nutrition”, “food”, “chocolate”, “dairy”, “whey protein”, “fatty acid”, or “drink” in the timeframe “January 2009-April 2020” within the PubMed database. Results: Fifty-three reviewed articles met eligibility criteria. They included 11 interventional clinical trials (seven randomized controlled trials and four uncontrolled open label studies) and 42 observational studies (17 case-control and 22 cross-sectional studies, and three descriptive studies). Conclusions: This review reinforces the notion of a rapidly growing exponential trend of interest in this subject by the scientific community. Acne-promoting factors include high GI/GL food, dairy products, fat food, and chocolate, whereas acne-protective factors include fatty acids, fruit, and vegetable intake. The role played by specific dietary components pertaining to different foods, as done for milk (full-fat/whole, reduced-fat, low-fat/skim milk), dairy products (milk cream, ice cream, yogurt, cheese, etc.), or chocolate (cocoa, dark/milk chocolate), remains an unsolved issue and objective of future research.